Membrane structure-function relationships in cell-mediated cytolysis. I. Effect of exogenously incorporated fatty acids on effector cell function in cell-mediated cytolysis.

The fatty acid composition of the membrane phospholipids of CTL memory cells restimulated with Con A can be altered significantly when selected exogenous fatty acids are present during the restimulation culture period. Such alterations also lead to significant changes in the subsequent cytolytic capacity of the regenerated CTL. Unsaturated fatty acids increase cytotoxicity, whereas saturated fatty acids lead to decreased cytotoxic function. The kinetics of the fatty acid effect on CTL function is the same as the kinetics of fatty acid incorporation into membrane phospholipids, suggesting that alteration of cytotoxicity results from altering membrane phospholipid fatty acid composition. The initial studies reported here suggest that this effect is mediated at the level of individual CTL, rather than through an alteration of CTL frequency in effector cell populations. Moreover, it seems unlikely that the fatty acids mediate their effect by altering membrane fluidity.